fix: Resolve Quick Start Wizard error display and policy creation issues

- Fixed error response format to send error message as string instead of boolean
- Enhanced error handling in QuickStartWizard to use handleApiError helper
- Improved policy creation with temp directory verification
- Added specific error detection for policy operations
- Fixed error display showing "true" instead of actual error message
- Ensured temp directory exists before writing policy files
- Added file access verification before executing MinIO commands
- Better cleanup of temporary files on failure

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

backend/src/middleware/errorHandler.middleware.js

@@ -57,7 +57,7 @@ const errorHandler = (err, req, res, next) => {
   const message = error.message || 'Internal Server Error';
 
   res.status(statusCode).json({
-    error: true,
+    error: message,
     message,
     ...(config.app.env === 'development' && { stack: err.stack }),
   });

backend/src/services/minio.service.js

@@ -100,6 +100,12 @@ class MinIOService {
         if (error.stderr.includes('Access Denied')) {
           throw new AppError('Access denied', 403);
         }
+        if (error.stderr.includes('already exists')) {
+          throw new AppError('Resource already exists', 409);
+        }
+        if (error.stderr.includes('policy')) {
+          throw new AppError(`Policy operation failed: ${error.stderr}`, 400);
+        }
       }
       
       throw new AppError(error.message || 'Command execution failed', 500);
@@ -232,9 +238,15 @@ class MinIOService {
 
       // Write policy to temp file
       const policyFile = path.join(this.tempDir, `${policyName}-${Date.now()}.json`);
+      
+      // Ensure temp directory exists before writing
+      await fs.mkdir(this.tempDir, { recursive: true });
       await fs.writeFile(policyFile, JSON.stringify(policy, null, 2));
 
       try {
+        // Verify the file was written
+        await fs.access(policyFile);
+        
         // Create and attach policy
         await this.executeCommand(
           `mc admin policy create ${this.alias} ${policyName} ${policyFile}`
@@ -328,16 +340,27 @@ class MinIOService {
     const policyFile = path.join(this.tempDir, `${policyName}-${Date.now()}.json`);
     
     try {
+      // Ensure temp directory exists before writing
+      await fs.mkdir(this.tempDir, { recursive: true });
+      
       await fs.writeFile(policyFile, 
         typeof policyDocument === 'string' ? policyDocument : JSON.stringify(policyDocument, null, 2)
       );
       
+      // Verify the file was written
+      await fs.access(policyFile);
+      
       await this.executeCommand(
         `mc admin policy create ${this.alias} ${policyName} ${policyFile}`
       );
       
       return { message: 'Policy created successfully', policyName };
+    } catch (error) {
+      // Clean up file if it exists
+      await fs.unlink(policyFile).catch(() => {});
+      throw error;
     } finally {
+      // Always try to clean up the temp file
       await fs.unlink(policyFile).catch(() => {});
     }
   }

frontend/src/components/Dashboard/QuickStartWizard.tsx

@@ -41,7 +41,7 @@ import {
 import { useTranslation } from 'react-i18next';
 import userService from '../../services/userService';
 import policyService from '../../services/policyService';
-import api from '../../services/api';
+import api, { handleApiError } from '../../services/api';
 
 interface QuickStartWizardProps {
   open: boolean;
@@ -219,8 +219,9 @@ const QuickStartWizard: React.FC<QuickStartWizardProps> = ({
 
       setCompletedSetup(results);
       setActiveStep(steps.length);
-    } catch (err) {
+    } catch (err: any) {
-      setError(err instanceof Error ? err.message : t('quickWizard:errors.creationFailed'));
+      const errorMessage = handleApiError(err);
+      setError(errorMessage);
       setIsCreating(false);
     } finally {
       setLoading(false);
@@ -297,7 +298,7 @@ const QuickStartWizard: React.FC<QuickStartWizardProps> = ({
               value={setupData.userPassword}
               onChange={(e) => setSetupData({ ...setupData, userPassword: e.target.value })}
               error={!!error && activeStep === 1}
-              helperText={error || t('quickWizard:user.passwordHelper')}
+              helperText={(error && activeStep === 1 ? error : '') || t('quickWizard:user.passwordHelper')}
               InputProps={{
                 endAdornment: (
                   <InputAdornment position="end">